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Neuropathogenesis of Tyzzer's organism in intranasally infected mice
Abstract:
The neuropathogenesis of Tyzzer's organism was comparatively studied in suckling and weanling mice after intranasal inoculation. In sucklings, suppurative rhinitis was produced in 24 hr postinoculation (p.i.) and organisms were detected in olfactory as well as supporting cells of the nasal mucosa. The lesions later developed to the lamina propria and propagation of organisms was seen within basal and glandular cells. On day 3 p.i., some organisms were found along with the olfactory nerve fibers and within neurons in the olfactory bulbs. Meningoencephalitis was produced with intraneuronal growth of bacteria on day 5 p.i. or later. On day 7 p.i., the brain lesions spread multifocally to the posterior parts and bacterial antigen in the nasal mucosa disappeared. In weanlings, infection was first established in the nasal mucosa and then some necrotized lesions were produced in the olfactory bulbs though much less in severity as compared to those of sucklings. Both suckling and weanling mice had necrotizing hepatitis while hemorrhagic enteritis was seen only in some sucklings.
Insights
Tyzzer's organism causes severe brain and nasal infections in young mice, with sucklings experiencing more intense neuropathogenesis than weanlings. The study details the progression of this bacterial infection in different age groups.
Area of Science:
- Veterinary Pathology
- Microbiology
- Neuropathology
Background:
- Tyzzer's disease is caused by Clostridium piliformis.
- Understanding the neuropathogenesis is crucial for disease management.
Purpose of the Study:
- To comparatively investigate the neuropathogenesis of Tyzzer's organism in suckling and weanling mice.
- To elucidate the route of infection and lesion development in the central nervous system.
Main Methods:
- Intranasal inoculation of Tyzzer's organism in mice of different age groups.
- Histopathological examination of nasal mucosa, olfactory bulbs, brain, liver, and intestines.
- Detection of bacterial antigen.
Main Results:
- Suckling mice developed severe suppurative rhinitis, olfactory bulb lesions, and meningoencephalitis with intraneuronal bacterial growth.
- Weanling mice showed milder olfactory bulb lesions compared to sucklings.
- Both age groups exhibited necrotizing hepatitis; hemorrhagic enteritis was observed in some sucklings.
- Bacterial antigen cleared from nasal mucosa by day 7 p.i. in sucklings.
Conclusions:
- Age significantly influences the severity of Tyzzer's organism neuropathogenesis.
- Suckling mice are more susceptible to severe neurological complications.
- The nasal route is a primary pathway for infection leading to central nervous system involvement.